Image capture system

Abstract

Currently, electronic imaging cameras use expensive array photodetectors instead of inexpensive linear photodetectors because they cannot scan linear detectors across the entire image within their exposure time and because the linear photodetectors do not capture sufficient photons to produce a high quality image. An image capture system is described that has a lens to form an image on an imaging plane, a linear detector mounted to preclude translational motion, a mirror for deflecting the image to the plane of the linear detector, and a mechanism that moves the mirror to scan the image across the linear detector.

What is claimed is: 
     
       1. A system for capturing an image, comprising: a. a detector;   b. a mirror located to deflect the image to the plane of the detector;   c. a mirror mechanism, attached to the mirror, the mirror mechanism moves the mirror;   d. a detector mechanism, attached to the detector, the detector mechanism rotates the detector synchronously with the movement of the mirror; and   e. a mirror trajectory having a continuum of mirror positions, at each mirror position, the plane of the mirror approximately bisects at approximately 90° a plurality of imaginary lines between the cells of the detector and their corresponding focal points on an image plane, the mirror mechanism moves the mirror along the mirror trajectory and the detector mechanism rotates the detector synchronously with the movement of the mirror along the mirror trajectory so the image focuses at the plane of the detector when the image scans across the detector.   
     
     
       2. The system, as in claim 1, wherein: the mirror trajectory requires both translational and rotational motion of the mirror;   the mirror mechanism translates and rotates the mirror; and   the detector mechanism rotates the detector at twice the rotational rate of the mirror.   
     
     
       3. The system, as in claim 1, wherein the plane of the mirror approximately bisects at approximately 90° all imaginary lines between all the cells of the detector and all their corresponding focal points on the image plane. 
     
     
       4. The system, as in claim 1, wherein the detector is a mosaic detector. 
     
     
       5. The system, as in claim 1, wherein the detector is a TDI detector having at least one chain of integrated photocell stages, the integrated photocell stages transfer charge between one another synchronously with the motion of the mirror on the mirror trajectory. 
     
     
       6. The system, as in claim 1, wherein the detector further comprises three detectors, each with a color filter. 
     
     
       7. The system, as in claim 6, wherein the detector further comprises groups of three detectors positioned side-by-side. 
     
     
       8. The system, as in claim 1, further comprising a second detector located at the image plane; and wherein the mirror further comprises a mirror that transmits light. 
     
     
       9. The system, as in claim 2, wherein the plane of the mirror approximately bisects at approximately 90° all imaginary lines between all the cells of the detector and all their corresponding focal points on the image plane. 
     
     
       10. The system, as in claim 2, wherein: at each mirror position, a first distances between the plane of the mirror and any cell on the detector equals a second distance between the corresponding focal point of that cell and the plane of the mirror. 
     
     
       11. A system for capturing an image, comprising: a. a detector;   b. a mirror positioned to deflect the image to the plane of the detector;   c. a mirror mechanism means, attached to the mirror, for translating and rotating the mirror;   d. a detector mechanism means, attached to the detector, for rotating the detector at twice the rotational rate of the mirror; and   f. a mirror trajectory means for continually focusing the image on the plane of the detector, the mirror trajectory means has a continuum of positions, at each mirror position, the mirror approximately bisects at approximately 90° a plurality of imaginary lines between the cells of the detector and their corresponding focal points on the image plane, the mirror mechanism means translates and rotates the mirror along the mirror trajectory means and the detector mechanism rotates the detector synchronously with the translation and rotation of the mirror along the mirror trajectory means.   
     
     
       12. The system, as in claim 11, wherein the mirror approximately bisects at approximately 90° all imaginary lines between all the cells on the detector and all their corresponding focal points on the image plane. 
     
     
       13. The system, as in claim 11, wherein at each mirror position, a first distance between the plane of the mirror and any cell on the detector equals a second distance between the corresponding focal point of that cell and the plane of the mirror. 
     
     
       14. The system, as in claim 11, wherein the detector is a mosaic detector. 
     
     
       15. The system, as in claim 11, wherein the detector is a TDI photodetector having at least one chain of integrated photocell stages, the integrated photocell stages transfer charge between one another synchronously with the motion of the mirror on the mirror trajectory. 
     
     
       16. The system, as in claim 11, further comprising a second detector located at an image plane; and   wherein the mirror further comprises a mirror that transmits light.   
     
     
       17. A method for capturing an image, comprising the steps of: a. positioning a mirror and a detector so the mirror deflects the image to the plane of the detector;   b. rotating and translating the mirror to scan the image across the detector;   c. rotating the detector at twice the rotational rate of the mirror; and   d. focusing the image at the plane of the detector, during the rotating and translating step, by continually positioning the mirror to approximately bisect at approximately 90° a plurality of imaginary lines between the cells of the detector and their corresponding focal points on the image plane.   
     
     
       18. The method, as in claim 17, wherein the step focusing the image further comprises continually positioning the mirror to make a first distance between the plane of the mirror and any cell on the detector equal to a second distance between the corresponding focal points of that cell and the plane of the mirror. 
     
     
       19. The method, as in claim 17, further comprising the steps of: scanning the image onto three photodetectors positioned side by side, each with a color filter. 
     
     
       20. The method, as in claim 17, further comprising the step of: transmitting a portion of the image through the mirror to a second detector located at the image plane.